This invention relates to a storage system, in particular, a logically partitioned storage system.
In order to reduce the cost of storage system management, there exists a storage consolidation technique with which plural storage systems are consolidated into a single large-scale storage system.
This storage consolidation has the following problem that concerns the running of a business.
Even after storage consolidation is performed, it is required to run a business as smoothly as before the consolidation, although a storage system is accessed by host computers in various forms and the processing capability required of the storage system varies depending on which access form is used. For instance, when the storage system is used as a database, a capability is required with which it is possible to process a large number of requests. Also, when the storage system is used to back up data that is accumulated from day to day, a capability of processing a large size of data is required.
As described above, the processing capability required of a storage system varies depending on which access form is used by host computers, so at the time of consolidation, a system administrator who is familiar with the configurations of old and new storage systems has to make the settings of the system. For instance, a storage system is proposed in which a certain service level selected by each customer is guaranteed to the customer through a service level guarantee contract and, when its storage performance is likely to drop, access is distributed by, for instance, migrating data stored in a storage volume, on which access is concentrated (see JP 2002-182859 A, for instance).
According to the invention described in JP 2002-182859 A, in a data center business undertaking out-sourcing of data management, it becomes possible to guarantee a certain service level based on a service level agreement(SLA) selected by each customer.